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<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>函数参数默认值</title>
  </head>
  <body>
    <script>
      // ES6 允许给函数参数赋值初始化
      // 1.形参初始值  具有默认值的参数,位置一般靠后
      add = (a, b, c = 0) => a + b + c;
      let result = add(1, 2);
      console.log(result);
      // 2.默认参数与解构赋值结合
      function connect({ host, username, password, port='3306' }) {
        console.log(host, username, password, port);
      }
      connect({
        host: "localhost",
        username: "root",
        password: "root",
      });
    </script>
  </body>
</html>
